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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2024

Abstract

Gray mold, caused by Botrytis spp., is a serious problem in Norway spruce seedling production in forest nurseries. From 2013 to 2019, 125 isolates of Botrytis were obtained from eight forest nurseries in Norway: 53 from Norway spruce seedlings, 16 from indoor air, 52 from indoor surfaces, and four from weeds growing close to seedlings. The majority of isolates were identified as B. cinerea, and over 60% of these were characterized as Botrytis group S. B. pseudocinerea isolates were obtained along with isolates with DNA sequence similarities to B. prunorum. Fungicide resistance was assessed with a mycelial growth assay, and resistance was found for the following: boscalid (8.8%), fenhexamid (33.6%), fludioxonil (17.6%), pyraclostrobin (36.0%), pyrimethanil (13.6%), and thiophanate-methyl (50.4%). Many isolates (38.4%) were resistant to two to six different fungicides. A selection of isolates was analyzed for the presence of known resistance-conferring mutations in the cytb, erg27, mrr1, sdhB, and tubA genes, and mutations leading to G143A, F412S, ΔL497, H272R, and E198A/F200Y were detected, respectively. Detection of fungicide resistance in Botrytis from Norway spruce and forest nursery facilities reinforces the necessity of employing resistance management strategies to improve control and delay development of fungicide resistance in the gray mold pathogens.

Abstract

The fall armyworm, Spodoptera frugiperda, situation in Africa remains a priority threat despite significant efforts made since the first outbreaks in 2016 to control the pest and thereby reduce yield losses. Field surveys in Benin and Mali reported that approximately one-week post-emergence of maize plants, the presence of fall armyworm (egg/neonates) could be observed in the field. Scouting for fall armyworm eggs and neonates is, however, difficult and time consuming. In this study, we therefore hypothesized that the optimum timeframe for the fall armyworm female arriving to lay eggs in sown maize fields could be predicted. We did this by back-calculating from interval censored data of egg and neonates collected in emerging maize seedlings at young leaf developmental stage. Early time of ovipositing fall armyworm after sowing was recorded in field experiments. By using temperature-based models to predict phenological development for maize and fall armyworm, combined with analytical approaches for time-to-event data with censored status, we estimated that about 210 accumulated Degree Days (DD) is needed for early detection of neonate larvae in the field. This work is meant to provide new insights on timely pest detection and to guide for precise timing of control measures.

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Abstract

The feed legislation allows the use of fish protein hydrolysates in feed for the same species in which it came from, since enzymatic hydrolysis degrades the proteins and eliminates potential prions, which have caused disease in mammals, but not in fish. In this trial, we investigated the effects of partially replacing dietary fishmeal (FM) with salmon protein hydrolysate (FPH) on the intestinal gene expression and microbiota. Atlantic salmon post smolts were either fed a control diet containing 30% fishmeal (FM), a 20% FM diet with 9% salmon hydrolysate (FPH-09) or a 10% FM diet with 18% salmon hydrolysate (FPH-18), until doubling of weight. Gene expression analysis by RNA sequencing of pyloric caeca (PC), midgut (MG) and hindgut (HG) revealed a downregulation of immunological genes involved in inflammation in the intestine of FPH-18 fed salmon compared to salmon fed the FM control. The gene expression of paralogous peptide transporters (PepT) was analyzed by real time quantitative PCR in PC, anterior midgut (AMG), posterior midgut (PMG) and HG of salmon fed all the three diets. The PepT1b paralog had highest relative expression levels in PC and AMG, suggesting that PepT1b is most important for peptide uptake in the anterior intestine. PepT1a was also mainly expressed in the PC and AMG, but at lower levels than PepT1b and PepT2b in the AMG. The PepT2b paralog had high levels of expression in AMG, PMG and HG indicating that it contributed significantly to peptide uptake in the posterior part of the gastrointestinal tract. The gut microbiota in the mucosa and digesta of the MG and HG, were dominated by the phyla Cyanobacteria and Proteobacteria, but also Firmicutes were present. The only dietary effect on the microbiota was the higher prevalence of the phyla Spirochaetes in the mucosa of FPH-18 fed salmon compared to the FM fed salmon. In conclusion, replacing FM with salmon hydrolysate reduced the expression of inflammatory markers in the Atlantic salmon intestine suggesting improved health benefits. The reduced inflammation may be related to the reduced FM content, potentially bioactive peptides in the hydrolysate and/or the altered gut microbial composition.

To document

Abstract

Import av planter med jord og andre vekstmedier til Norge utgjør en betydelig risiko for innføring av planteskadegjørere som kan skade landbruket og naturlige økosystemer. Denne risikoen kan reduseres ved å stille strengere importkrav. Dette er hovedkonklusjonen i en risikovurdering Vitenskapskomiteen for mat og miljø (VKM) har gjort for Mattilsynet og Miljødirektoratet. Oppdragsgiverne har bedt VKM vurdere risikoen forbundet med jord og andre vekstmedier som følger med importerte planter. De har også bedt oss vurdere hvor effektive ulike risikoreduserende tiltak er for å forhindre innførsel av planteskadegjørere. Bakgrunn Planteskadegjørere som sopp, bakterier, nematoder og insekter kan komme til Norge med jord og andre vekstmedier som følger med importerte planter fra Europa. Slike skadegjørere kan forårsake alvorlig skade på norsk plantehelse. Selv med dagens kontrolltiltak, er det høy sannsynlighet for at skadelige organismer kan komme inn i landet. Risiko VKM har identifisert flere planteskadegjørere som er knyttet til import av jord og andre vekstmedier, og vurdert risikoen for negative effekter på norsk plantehelse: Planteskadegjørere i jord og vekstmedier: Jord og vekstmedier kan inneholde skadelige organismer som kan etablere og spre seg i Norge, noe som kan skade landbruket og økosystemer. Høye importvolumer av planter med jord og vekstmedier øker sannsynligheten for innføring av skadegjørere. Spesielt import fra land som Nederland, Tyskland, Danmark og Sverige medfører høy risiko, fordi mesteparten av plantene som importeres til Norge kommer fra disse landene. Nåværende regelverk og kontrolltiltak, som i stor grad baserer seg på visuell inspeksjon, er ikke tilstrekkelige for å oppdage alle skadegjørere. - Når vi kjøper levende planter, vokser de i et tilhørende vekstmedium. Denne klumpen rundt rota kan inneholde skadegjørere, som insekter, sopp, rundormer eller bakterier. Kanskje har planten levd mange år i dette vekstmediet før den kommer til Norge – det kan ha utviklet seg et helt lite økosystem nede i potten. Når vi importerer busker og trær er det dermed stor sannsynlighet for at de har med seg organismer vi ikke ønsker inn i landet. Disse organismene kan gjøre alvorlig skade på norsk plantehelse, og påvirke både landbruket og naturlige økosystemer, sier fagansvarlig Paal Krokene, som sitter i VKMs faggruppe for plantehelse, og har ledet arbeidet med rapporten. Risikoreduserende tiltak VKM er også bedt om å identifisere flere tiltak som kan redusere risikoen for uønsket innførsel av planteskadegjørere: Strengere krav til import av jord og andre vekstmedier, inkludert bruk av sterile eller varmebehandlete vekstmedier. Innføring av obligatorisk grensekontroll og mer omfattende inspeksjoner av planter importert med jord og vekstmedier. Forbud mot import av planter med jord og andre vekstmedier fra områder med kjent høy risiko for å huse planteskadegjørere. Bruk av DNA-analyser og andre avanserte metoder for å bedre påvise skadegjørere i vekstmedier, også i tilfeller der plantene ikke har synlige tegn på infeksjon. Konklusjon Import av planter med jord og andre vekstmedier utgjør en betydelig risiko for introduksjon av planteskadegjørere. Strengere kontrolltiltak og regelverk vil kunne bidra til å redusere risikoen for innførsel av skadelige organismer og beskytte norsk plantehelse.

Abstract

• For more than 20 years, methyl jasmonate (MeJA) has been used to study inducible defenses in conifers and to increase tree resistance to pests and pathogens. Despite the numerous studies on the subject, no attempts have been made to summarize or quantify how MeJA affects resistance and growth in conifers. Here we present a quantitative meta-analysis of the effects of MeJA treatment on the conifer genera Pinus and Picea, two of the most economically and ecologically important tree genera in boreal, temperate, and alpine forests. • A literature search yielded 120 relevant papers. We summarized the key experimental methods used in these papers and performed a meta-analysis of how MeJA affects tree growth and resistance to pests and pathogens. • The results show that MeJA negatively affects tree growth, with an overall effect size of −0.63. The overall effect size of MeJA for tree resistance was −0.76, indicating that MeJA treatment significantly reduces tree damage caused by biotic stressors. • Although our meta-analysis shows that MeJA is effective in enhancing conifer defenses, there are still gaps in our understanding of the durability and ecological consequences of MeJA treatment. We provide suggestions for how future research should be conducted to address these gaps.